Propane-1,3-diyl bis-(pyridine-4-carboxyl-ate)

The title compound. C(15)H(14)N(2)O(4), (I), has a gauche-gauche (O/C/C/C-O/C/C/C or GG) conformation and is a positional isomer of propane-1,3-diyl bis-(pyridine-3-carboxyl-ate), (II). The mol-ecule of (I) lies on a twofold rotation axis, which passes through the central C atom of the aliphatic chain, giving one half-mol-ecule per asymmetric unit. There is excellent agreement of the geometric parameters of (I) and (II). The most obvious differences between them are the O/C/C/C-O/C/C/C torsion angles [56.6 (2)° in (I) and 174.0 (3)/70.2 (3)° in (II) for GG and TG conformations, respectively] and the dihedral angle between the planes of the aromatic rings [80.3 (10)° in (I) and 76.5 (3)° in (II)]. The crystal structure is stabilized by weak C-H⋯ N and C-H⋯ O hydrogen bonding.